1. A and B can do a piece of work in 7 days. With the help of C they finish the work in 5 days. C alone can do that piece of work in?
A. 1 day
B. 10 days
C. 30 days
D. 32 days

Answer: Option C

Explanation:C = 1/5 – 1/6 = 1/30 => 30 days

2. Ravi can do a piece of work in 30 days while Prakash can do it in 40 days. In how many days will they finish it together?
A. 17 1/7 days

B. 27 1/7 days

C. 23 2/7 days

D. 16 4/11 days

Answer: Option A

Explanation: 1/30 + 1/40 = 7/120

120/7 = 17 1/7 day

3. Anil can do a work in 15 days while Sunil can do it in 25 days. How long will they take if both work together?
A. 3 4/9 days

B. 8 4/9 days

C. 9 3/8 days

D. 6 3/8 days

Answer: Option C

Explanation: 1/15 + 1/25 = 8/75

75/8 = 9 3/8 days

4. A can do a job in 18 days and B can do it in 30 days. A and B working together will finish twice the amount of work in ——- days?
A. 21 ½ days

B. 22 ½ days

C. 23 ½ days

D. 12 ½ days

Answer: Option B

Explanation: 1/18 + 1/30 = 8/90 = 4/45

45/4 = 11 ¼ *2 = 22 ½ days

5. A can do a piece of work in 10 days and B can do it in 15 days and C can do it 20 days. They started the work together and A leaves after 2 days and B leaves after 4 days from the beginning. How long will work lost?
A. 8 2/3 days